Lab Safety
Nanoparticles
Background
• The ASTM Committee on Nanotechnology has defined a nanoparticle as a
particle with lengths in two or three dimensions between 1 and 100
nanometers (nm). Nanoparticles can be composed of many different base
materials and may be of different shapes including: nanotubes; nanowires;
and crystalline structures such as fullerenes and quantum dots.
• Nanoparticles or nanomaterials used in laboratory experiments will be
likely in one of three forms: a powder, in suspension, or in a solid matrix.
Safety Issues – Why are we concerned?
• The ultrasmall particle size permits the particles to be carried deeply into
tissues
• The molecular structure of nanoparticles and the relatively greater surface
area confer on these particles different chemical reactivities than for
larger structures made from the same elements or molecules.
• Nanoparticles present a unique challenge from an occupational health
perspective as there is a limited amount of toxicological data currently
available for review. The National Institute of Occupational Health and
Safety (NIOSH) and other agencies are currently studying this issue, and
improved guidelines for handling and disposal will be forthcoming.
Currently, agencies charged with providing safety guidelines, including
NIOSH, the NIH and the EPA, promote the incorporation of cautionary
measures in research, with a view toward minimizing or eliminating
exposures to nanoparticles.
Exposure Pathways
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Inhalation. Respiratory absorption of airborne nanoparticles may occur through
the mucosal lining of the trachea or bronchioles, or the alveolus of the lungs.
Certain nanoparticles appear to penetrate deep into the lungs and may translocate
to other organs or pass through the blood-brain barrier Thus, whenever possible,
nanoparticles are to be handled in a form that is not easily made airborne, such as
in solution or on a substrate.
Dermal absorption. In some cases nanoparticles have been shown to migrate
through skin and be circulated in the body. If the particle is carcinogenic or
allergenic, even tiny quantities may be biologically significant. Skin contact can
occur during the handling of liquid suspensions of nanoparticles or dry powders.
Skin absorption is much less likely for solid bound or matrixed nanomaterials.
Ingestion. As with any material, ingestion can occur if good hygiene practices are
not followed. Once ingested, some types of nanoparticles might be absorbed and
transported within the body by the circulatory system.
Injection. Exposure by accidental injection (skin puncture) is also a potential route
of exposure, especially when working with animals or needles.
Laboratory Safety Guidelines for
Handling Engineered Nanoparticles
The current practices for working with engineered nanoparticles safely are essentially
the same as one would use when working with any research chemical of unknown
toxicity
If handling or transporting materials outside of a glovebox, workers should wear
protective equipment, including
•
Latex or nitrile gloves when handling nanoparticle powders and nanoparticles in
suspension (glove changes should be performed frequently); Outer gloves should
always be removed inside the hood or under the influence of local exhaust
ventilation and placed into a sealed bag. This will prevent the particles from
becoming airborne.
•
Chemical splash goggles when working with nanomaterials in suspension or dry
powdered form;
•
Lab coats. Lab coats should be laundered on a periodic basis. Do not take lab coats
home for laundering;
The use of respirators is not generally required for worker protection if you work in a
ventilated area.
• When purchasing commercially available nanoscale materials, be
sure to obtain the Material Safety Data Sheet (MSDS) and to
review the information in the MSDS with all persons who will be
working with the material. Note, however, that given the lack of
extensive data on nanoparticles, the information on an MSDS
may be more descriptive of the properties of the bulk material.
• Nanoparticle solutions may be handled on the lab bench once
placed in solution.
• Transport of nano-materials should employ a sealed secondary
containment device.
• Work surfaces should be wet-wiped regularly – daily is
recommended. Because many engineered nanoparticles are not
visible to the naked eye, surface contamination may not be
obvious. The cleaning solution should be compatible with the
vehicle in which the nanoparticles are suspended.
• To prevent ingestion, eating and drinking and chewing gum are
not allowed in laboratories
• Report any safety concern
Managing Spills
• All spills involving nanoparticles should be treated like
a hazardous material spill and cleaned up immediately.
• The person cleaning up should wear double nitrile
gloves and either vacuum up the area with a HEPA
filtered vacuum or wet wipe the area with towels, or
combination of the two.
• For spills that might result in airborne nanoparticles,
proper respiratory protection should be worn, such as
a respirator with NIOSH-approved filters that are rated
as N-, R- or P-100 (HEPA).
• Do not brush or sweep spilled/dried nanoparticles.
Waste Disposal Procedures
• Since the toxicology and environmental fate of
nanoparticles is still largely unknown, all
nanoparticle waste (solid material and liquids)
should be conservatively managed as
hazardous waste.
• Nanoparticle waste must be placed in an
appropriate container and labeled for
chemical content in compliance the hazardous
waste management requirements.